<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>特殊状态伪类选择器示例</title>
    <style type="text/css">
        div:empty {
            width: 100%;
            height: 30px;
            background-color: lightblue;
        }
        div :not(p) {
            text-shadow: 0 0 10px #000;
        }
    </style>
</head>
<body>
    <div></div>
    <div>
        <p>第一个p标签</p>
        <p>第二个p标签</p>
        <span>第一个span标签</span>
        <span>第二个span标签</span>
    </div>
</body>
</html>